780 MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



as the ray-fungus (Fig. 164). Its relation to the disease of actinomycosis 

 is probably specific but it is frequently aided by pus producing bacteria. 

 It is believed that the Actinomyces vegetate on various grasses, 

 especially wild barley, and that infection occurs by inoculation with the 

 awns and barbs of such grasses through the mucous membrane of the 

 mouth or other portions of the alimentary tract. 



FIG. i6;. Actinomycosis. Actinomyces bovis. Preparation from a pure culture. 

 Xiooo. (After Williams.) 



Infection by inoculation is the most common method of introducing 

 the disease; but infection by inhalation evidently occurs in some cases. 

 It seems probable that some special stage of development for the Acti- 

 nomyces is necessary either within the diseased animal body or upon 

 some plants, in order that it may be able to infect animal bodies, for 

 direct inoculation by pus has usually given negative results. Inocula- 

 tion by bits of diseased tissue occasionally gives positive results. 



It is evidently not a producer of active toxins for the disease dis- 

 turbances are apparently due to harmful growth in the tissues and to 

 secondary infection. 



Suppuration is one of the conspicuous features as is also the develop- 

 ment of much new granulation tissue which tends to degenerate at the 

 center. Soft organs affected by this parasite show a tendency to multi- 

 ple abscesses. 



